Hello guys , I am making a 2D airfoil simulation using OpenFoam turbulence modele (k kl omega) once i launche my calculations using pimpleFoam it starts okk but than diverges for the k Kl and Omega . While for the time step continuity Error evrrything is Okk.
1/- is this related to my mesh or it is because of the solver options that i need to Change . 2/- also for my boundary conditions i ve followed those used in the openfoam tutorial in tut/incopressible/pimpleFoam/RAS/elipseKKlomega. 3/-for the kl value i only used a small value of 1e-5 ( is there a way to calculate it or the value i used is okk?) 4/-for the mesh i used it is combined of two types of mesh where i ve used mergemeshes and stitchmesh to get my final mesh thats why you find front1 front 2 back 1 and back2
You don't give enough information for an answer. (And for security most of us do not open attachments) I suggest first you try running the code with inviscid and a one-equation model (SA perhaps) to see if it is mesh or time step related. If you have separation (high alpha), running a 2D simulation with RANS is not going to give you an accurate answer. Oh yes, and don't assume we are all "guys"...
IF the problem diverges, you might need to increase the number of inner iterations performed at every physical time-step. You can also change the turbulence model to one-equation model to see whether it is a turbluence model problem or not and then we could answered you in more details.
Marilyn J. Smith : Thank you for the Replay and the Note and i ll take it in consideration ^ - ^ .
Mohamed Sayed Marilyn J. Smith
I ve solved the Problem of the divergence problem and now my calculations are converging but i still have a quetions Hope you can help me out with It.
for my simulation using the Kkl Omega turbulence Model My Y + value is :
wing y+ : min = 4.22979, max = 18.5785, average = 15.0189
is this value okk? or should i get it More than 30 or less than 5 , since i am using the nutLowReWallFunction.?
Dear Oussama
check the Y+ of your grid near the airfoil wall better to be less than 1
make sure your time step is small enough
consider standard k-e for the initial solution
best wishes
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